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M a n u f a c t u r e r s a n d d i s t r i b u t o r s o f s e a l i n g a n d j o i n t i n g m a t e r i a l s .
S e m i - M e t a l l i c G a s k e t s
Novus Sealing and our distributors are fully committed to ensuring our customers throughout the world receive the highest level of quality and technical support
for our products and services. Our technical specialists can provide expertise on all issues associated with sealing performance.
Certificate No. 18566BS EN ISO 14001:2004
Certificate No. 18566BS EN ISO 9001:2000
AS/NZS ISO 9001:2000Lic: QEC 5296SAI Global
Novus Sealing Limited, Hunsworth Lane, Cleckheaton, West Yorkshire, England BD19 3UJ
Tel: +44 (0)1274 878787 Fax: +44 (0)1274 862588 www.novussealing.com e-mail:[email protected]
Novus Sealing Pty Ltd., 15 Vinnicombe Drive, Canning Vale, Perth, Western Australia 6155
Tel: +61 (08) 9455 2155 Fax: 61+ (08) 9455 2165 www.novussealing.com.au e-mail:[email protected]
S E A L I N G L I M I T E D
S E A L I N G P T Y L T D
Novus Sealing Technology (Shanghai) Ltd., Room 1002, No.738 Shang Cheng Road, Shanghai, China 200120, P.R. China
Tel: +86 21 6102 8975 Fax: 0086 21 6102 8976 www.novussealing.com.cn e-mail:mailto:[email protected]
SEALING TECHNOLOGY
W O R L D W I D E
S E A L I N G L I M I T E DNovus Sealing Limited, 87 Radio Street, Alberton North, Johannesburg, Gauteng, South Africa
Tel: +27 (0)11 865 4807 Fax: +27 (0)11 902 2173 www.novussealing.com.za e-mail:[email protected]
S E A L I N G L I M I T E D
Novus Sealing Limited manufacture and
supply a variety of high quality sealing products
designed for flange applications in the industrial
and manufacturing sectors. The Novus ethos is to
provide honesty, reliability and a high level of
service and dependability through all aspects of
its business, adding value to its products and
ensuring a sustained competitive edge.
Over the years Novus have enhanced their
technical facilities to develop new products and
provide guidance and training programmes for
some of the world’s largest chemical and
petrochemical plants. Novus have a dedicated
Research & Development Team who ensure high
quality technical support for all Novus products.
Novus constantly look to provide a balanced
mix of quality sealing products with a warmth
of service.
Novus Sealing continues to invest in quality and
environmental systems such as ISO9001,
ISO14001 and are currently working towards
the ISO18001 approval. Novus also supply
API6a approved Ring Type Joints for the oil
industry. Novus Sealing has won the highly
commended “International Business of the Year”
award and has developed its training facilities in
the UK as well as opening new operations in
Australia, South Africa and China. Novus
products are traditional in function but the
company’s outlook is progressive and evolving.
Semi-Metallic Gaskets
ContentsThis brochure outlines our semi-metallic range of products
and provides guidelines on their correct selection, storage
and assembly.
For more information on any of the areas covered
please contact our sales or technical support team.
Camprofile, Spiral Wound, Corrugated and Metal Jacketed Gaskets
Welding and profilingHigh technology and high performance
welding and profiling machines provide high
integrity quality fabrication through all our
semi metallic product range.
SpecificationThe specifications for each order are contin-
ually checked on every product. Accuracy
and precision in every application ensures
that quality standards are second to none.
ProductionThe dedicated production facility for
semi-metallic products has been purpose built
for efficiency and ease of order management.
The PeopleAll our production staff undergo a
continuous training programme which
includes customer awareness, product
application and industry courses.
ManufacturingThe fabrication of semi - metallic products is
subject to stringent quality control and test
procedures.
Selection Guide Pages 1 - 2
Camprofile Gaskets Pages 3 - 6
Spiral Wound Gaskets Pages 7 - 11
Lamons Novus WRI-LP Page 12
Corrugated Gaskets Pages 13 - 14
Metal Jacketed Gaskets Pages 15 - 16
Control of Flanged Joints Pages 17 - 20
Installation Guide Page 20
1
Camprofile Gaskets
Camprofile Gaskets consist of a metal core,
generally stainless steel, with concentric
grooves on either side. A sealing layer is nor-
mally applied to both faces and depending on
the service the material for this layer can be
graphite, PTFE, Novus Sheet material or metal
(e.g. Aluminium or silver). Camprofile gaskets
are ideal for both standard pipe and heat
exchanger applications.
Spiral Wound Gaskets
Spiral Wound Gaskets consist of a ‘V’ shaped
metal strip spirally wound in combination with
a soft filler material, normally graphite, PTFE
or Hi-Temp. The metal strip provides outstand-
ing recovery whilst the flexible filler ensures
excellent sealing. Depending on the applica-
tion the gasket can be specified with outer
and/or inner rings.
Corrugated Metal Gasket
Corrugated Metal Gaskets consist of a corru-
gated metal core, normally stainless steel,
with a soft facing layer applied to each face.
The corrugations provide resilience and reduce
the sealing surface area of the gasket while
the soft layer ensures outstanding sealing,
even at low loads. Particularly suited as a
replacement to metal jacketed gaskets.
Spiral Wound GasketsCamprofile Gaskets Corrugated Gaskets
Metal Jacketed Gaskets
Metal Jacketed Gaskets consist of soft filler
material encapsulated in a metallic material.
The filler material provides the gasket with
compressibility and resilience while the jacket
provides compressive strength and blow
out resistance.
Metal Jacketed Gaskets
Many factors affect the suitability of a
gasket in a given application making
it often difficult to determine which
is the correct one for the duty. In heat
exchanger applications, factors such as
relative flange movement can complicate
gasket selection still further, therefore it is
important that the attributes of each gasket
type are fully understood.
To help you make an informed choice on
gasket selection the following table gives
the advantages and disadvantages of each
gasket under various conditions.
This table should be used as a general guide
for selection only.
Tightness
Handling
Thermal Cycling
Low Seating Stress
High Seating Stress
Narrow Flange Width
Emissions
Recycling
Camprofile Gaskets Spiral Wound GasketsCorrugated Gaskets Metal Jacketed Gaskets
E x c e l l e n t E x c e l l e n tE x c e l l e n t A v e r a g e
A v e r a g e
A v e r a g e
A v e r a g e A v e r a g eE x c e l l e n t
E x c e l l e n t
E x c e l l e n t
E x c e l l e n t
E x c e l l e n t A v e r a g e
A v e r a g e
E x c e l l e n t
E x c e l l e n t
E x c e l l e n t
E x c e l l e n t
E x c e l l e n t
G o o d
G o o d
G o o d G o o d
E x c e l l e n t A v e r a g eE x c e l l e n tE x c e l l e n t
Y e s N oN o N o
2
Full details of all dimension tables
can be found on our website -
www.novussealing.com
Camprofile GasketCharacteristics
Camprofile gaskets consist of a metal core,
generally stainless steel, with concentric
grooves on either side. A sealing layer is
usually applied on both sides and depending
on the service duty the material for this layer
can be graphite, PTFE (Teflon), Novus sheeting
material or metal (e.g. aluminium or silver).
Camprofiles can be used without sealing
layers to provide an excellent seal but there
is a risk of flange surface damage especially
at high seating stresses. The sealing layers
protect the flange surface from damage in
addition to providing an excellent seal at
low bolt stress.
Properties
The wide seating stress range (minimum to
maximum seating stress) of the gasket
makes it:
Highly suitable for varying temperatures
and pressures.
Less sensitive to assembly faults (inaccu-
rate bolt tightening)
Suitable for light and heavy designed
flanges.
Dependent upon the layer material cam-
profile gaskets can resist temperatures up
to 1000OC.
Resistant to media pressures > 400 bar.
When assembled the remaining thickness
of the sealing material is extremely low
(0.1 - 0.2mm), thus reducing leaks, fail rates
and environmental pollution.
The gasket will not damage the flange sur-
face and can be easily removed.
Camprofile cores are re-usable after clean-
ing, inspection and relayering with new
sealing material. This is of particular inter-
est in the case of heat exchanger gaskets.
Reduces maintenance costs and leakage -
thanks to camprofile’s high sealing perfor-
mance and reliability.
Seating Stress Range
The Camprofile gasket offers reliable sealing
performance when seated within the following
seating stress ranges
Flange Surface Finish
The recommended flange surface finish for
camprofiles with sealing layers is from 3.2 to
6.3µm Ra (125-250 RMS), this is also referred
to as a smooth finish.
Core Thickness
Core thickness depends on the assembly
circumstances. Generally a 3mm core is
recommended but for large diameter gaskets
above 1.5m it is advisable to use a 4mm core
for purposes of stability.
M18, M20, M21Advantages of parallel root cores
Uniform spread of stress at the cams.
Uniform spread of stress across the
flange surface.
M38, M40, M41Advantages of convex root cores
Highly suitable for underbolted flanges.
Effective seal at low stress.
The gasket design ensures a high seating stress
area in the centre of the seal face and a lower
seating stress towards the outside edges of the
seal face.
M18L
Parallel root core with integral
centering ring
M20L
Parallel root core without
centering ring for male/female,
torque & groove and grooved
flanges
M21LM
Parallel root core with floating
centering ring attached outside
the sealing ring
Gasket Profiles
All profiles feature as standard a 1mm cam
pitch and a maximum groove depth of
0.5mm. Alternative profiles are available on
request e.g. 1.5mm cam pitch and a maximum
groove depth of 0.75mm (DIN profile).
M38L
Convex root core with integral
centering ring
M40L
Convex root core without
centering ring for male/female,
tongue/groove and
grooved flanges
M41LM
Convex root core with floating
centering ring, attached outside
the sealing ring
With or without centering ring
Camprofile gaskets with centering rings ensure
optimum gasket positioning between the bolts.
Layer Material
Graphite
PTFE
Novus Sheet
Silver
Hi-Temp
Min(N/mm2)
20
20
40
125
40
Opt(N/mm2)
90
90
125
240
100
Max(N/mm2)
400
350
200
450
250
Seating Stress (20OC)
The above are based on parallel form gaskets.
The values have slight variations for convex
forms of camprofiles.
Styles M21LM and M41LM are available in
4mm thickness only due to their construction.
Loose or integral centering rings
Thermal shock conditions may damage cam-
profiles with integral centering rings (thermal
tension may cause cracks in the core). This is
prevented by using camprofile gaskets with
loose or floating guide rings.
The centering rings on styles M21LM and
M41LM allow for expansion and contraction
without reactionary forces being applied to the
core. Note: camprofiles are available with pre-
determined breaking points.
Optimal gasket performance is ultimately
ensured by the quality of flange surface finish
and correct assembly.
Camprofile Gasket shapes
In addition to the round gaskets, camprofiles
can be made in a variety of shapes, oval,
rectangular and exchanger with pass bars.
Correctly dimensioned gasket drawings are
required to make non-standard gaskets and
gasket shapes.
Profile Selection
Recommended
>1.5mM21LMM41LM
Core Thickness
(mm)
Thickness afterAssembly
(core + layers)(mm)
3
4
approx 3.1 - 3.4
approx 4.1 - 4.4
Camprofile Gaskets Camprofile Gaskets
43
Camprofile Gaskets
Core Material Selection
Core Material
The core material is generally fabricated in
material identical to the piping system to
prevent corrosion problems.
Stainless Steel 316L camprofiles cores are
generally used with carbon steel pipe systems
to prevent gasket corrosion.
The recommended camprofile metal cores are
shown in the table below.
Camprofile Gaskets M21L and M41L
During recent years, modified gaskets have been
introduced and these are now included in our
manufacturing programme.
Generally camprofile gaskets are manufactured
with a 0.5mm thick floating centering ring.
Based on intensive research and practical tests,
in cooperation with major users, a 1.5mm thick
floating centering ring was developed featuring
a unique outer edge attachment.
The M21LM and M41LM styles offer the
following advantages:
The floating centering ring is stable and free from
expansion stresses.
No distortion of the centering ring by the threads
of the bolts, as sometimes occurs in vertical
assemblies, causing the camprofile to be posi-
tioned eccentrically. This also increases the possi-
bility of re-use, reducing costs.
User friendly - the 1.5mm thick guide ring reduces
the risk of operator injury during handling.
The floating guide ring allows for expansion
without applying mechanical stress to the cam-
profile core.
Layer Material Selection
The following table may be used to determine
the appropriate sealing layer material. Novus
recommend the use of graphite layers for most
applications. Only in cases where graphite may
cause media pollution, or is not chemically
resistant, should an alternative material layer
be chosen.
Layer Material
Graphite
Graphite APX2
PTFE
Novus Sheet
Silver
Hi-Temp
Hi-Temp + APX2
Temperature(OC)
Min Max
-200 450
-200 500
-200 260
-100 250
-200 750
-200 1000
-200 800
MaximumOperatingPressure
(Bar)
400
400
150
100
250
20
100
Gas Tightness
Good
Good
Good
Good
Good
Average
Good
Application
Aggressive Media
Aggressive Media
Aggressive Media
Gas and Liquids
Aggressive Media
Gases
Gases
Graphite
Graphite is a universal, high quality, non
asbestos sealing material featuring:
Very good chemical resistance.
Resistance to high fluctuating tempera-
tures and pressures.
Non ageing properties.
Excellent gas tightness qualities.
PTFE
PTFE is a high quality synthetic material
featuring:
Excellent chemical resistance.
Temperature resistant up to 260OC.
Good ageing resistance.
Excellent gas tightness.
Novus Sheet
Novus Sheet materials consist of synthetic fibre
compounds with rubber binders and mineral fillers.
Silver
Silver is a precious metal combining excellent
gas tightness and chemical resistance proper-
ties. Generally used in applications requiring
gas tightness at elevated temperatures.
The standard graphite used has an ash content
of < 2% and chloride content of < 50ppm.
Other graphite qualities are available on request.
Hi-Temp
Hi-Temp is a mica based material suitable for
high temperature applications, often used in
combination with graphite up to tempera-
tures of 800OC.
Material(Trade Name)
Low Carbon Steel
Stainless Steel 304
Stainless Steel 304 L
Stainless Steel 309
Stainless Steel 316
Stainless Steel 316 L(1)
Stainless Steel 316 Ti
Stainless Steel 321
Stainless Steel 347
Stainless Steel 410
254SMO
Duplex
Super Duplex
Aluminium
Silver
Copper
Nickel 200
Monel 400
Inconel 600
Inconel 625
Incoloy 800
Incoloy 825
Hastelloy B2
Hastelloy C276
Titanium
R St 3.72
X5 Cr Ni 18
X2 Cr Ni 18 9
X15 Cr Ni Si 20 12
X5 Cr Ni Mo 18 10
X2 Cr Ni Mo 18 10
X10 Cr Ni Mo Ti 18 10
X10 Cr Ni Ti 18 9
X10 Cr Ni Nb 18 9
X6 Cr 13
X1CrNiMoCuN20187
X2 Cr Ni Mo N 22 5 3
X2 Cr Ni Mo N 25 6 3
A1 99 5
-
SF - Cu
Ni 99 2
Ni Cu 30 Fe
Ni Cr 15 Fe
Ni Cr 22 Mo 9 Mb
X10 Ni Cr A1 Ti 3220
Ni Cr 21 Mo
Ni Mo 28
Ni Mo 16 Cr 15 W
Ti 99 8
-
1.4301
1.4306
1.4828
1.4401
1.4404
1.4571
1.4541
1.4550
1.4000
1.4547
1.4462
1.4410
3.0255
-
2.0090
2.4066
2.4360
2.4816
2.4856
1.4876
2.4858
2.4617
2.4819
3.7025
-
304
304L
309
316316L
316Ti
321
347
410
S31254
S31803/32205
S32750
A91050
-
C12200
N02200
N04400
N06600
NO6625
N08800
N08825
N10665
N10276
R50400
-
304S15/16/13
304S11
309S24
316S16
316S11/13
320S31
321S12/49/87
347S31
410S21
-
318S13
-
1B
-
C106
3072-76 NA11
3072-76 NA13
3072-76 NA14
3072-76 NA21
3072-76 NA15
3072-76 NA16
-
-
TA2
DINSpecification
DINMaterial No.
AISAASTMUNS
B.S.
- 40
-250
-250
-100
-100
-100
-100
-250
-250
-20
-100
-40
-40
-250
-250
-250
-250
-125
-100
-50
-100
-100
-200
-200
-250
500
550
550
1000
550
550
550
550
500
850
500
300
300
300
750
400
600
600
950
450
850
450
450
450
350
7.85
7.90
7.90
7.90
7.90
7.90
7.80
7.90
7.90
7.80
8.00
7.80
7.80
2.71
10.50
8.90
8.90
8.80
8.40
8.44
8.00
8.14
9.20
8.90
4.50
Temperature(OC)
Minimum Maximum
Density(gr/cm2)
(1) Standard Material for Camprofile Gaskets
Graphite APX 2
Inhibited grade for oxidation resistance. Ideal
for use at temperatures above the limit recom-
mended for standard graphite grades. Often
used in combination with Novus Hi-Temp for
high temperature applications.
Please specify the following when ordering
camprofile gaskets.
Style of camprofile gasket.
Nominal pipe bore, pressure rating and
flange standard.
Materials of core and sealing layer.
For non standard flanges please specify
gasket dimensions.
The following example illustrates how to order a
camprofile gasket (information in bold print is
stamped on the centering ring - if present;
otherwise the information is printed on the
packaging):
M41LM - Style M41LM - convex root-form
camprofile with floating externally attached
centering ring.
4”-300lbs - The gasket is suitably dimen-
sioned for 4” flanges, 300lbs pressure rating.
316L - Camprofile core of 316L stainless steel.
Graphite - Graphite sealing layer
How to Order
Camprofile Gaskets
5 6
Identification
S
S304
S304L
S309
S316
S316L
S316TI
S321
S347
S410
6Mo
2205
2507
AL 1050
Ag
Cu
Ni200
400
600
625
800
825
B2
C276
Ti2
Spiral Wound Gaskets
The sealing element of the spiral wound gasket
consists of a V-shaped metal strip spirally
wound in combination with a soft sealing
material filler. The metal strip provides out-
standing resilience, while the flexible sealing
filler guarantees excellent sealing.
Due to this combination of materials, the spiral
wound gasket is suitable for sealing under
severely fluctuating temperature and pressure
conditions. Depending on the application the
spiral wound gasket can be specified with
outer and/or inner rings.
Spiral Wound Gaskets
Properties
Spiral wound gaskets are suitable for use
across a wide gasket stress range.
Spiral Wound gaskets can be used
to seal fluid pressures up to 400
bar and from cryogenic
temperatures up to 1000OC.
Spiral Wound gaskets are
robust and simple to install.
The outer guide ring simplifies
assembly and prevents blow-
out of the gasket.
By combining different winding
materials and metals, the gasket
can be tailored to suit a wide variety
of operating conditions.
The gasket is easy to remove after service
and does not cause any damage to the
flange faces.
Spiral Wound Gaskets
Gasket Stress Range
Novus spiral wound gaskets should preferably be
mounted within the gasket stress ranges shown
in this chart to ensure leak free connections.
Flange Surface Finish
The recommended surface roughness of
the flange faces, between which a spiral
wound gasket is to be mounted, is 3.2 - 6.3
µm Ra (125 - 250 RMS), also referred to as
smooth finish.
Gasket Stress Range:
Single side confined Both sides confined
Gasket Stress (20OC) Gasket Stress (20OC)Filler
Min Opt Max Min Opt Max (N/mm2) (N/mm2) N/mm2) (N/mm2) (N/mm2) (N/mm2)
Graphite 50 95 180 50 120 400
PTFE 50 80 130 50 110 250
Hi-Temp 55 95 130 50 120 250
Type SGThe standard spiral wound gasket format identi-
cal to Novus RF1 but fitted with an outer center-
ing ring (applied to raised face flanges). An inte-
gral centering guide ring ensures fast, accurate
centering of the gasket on the flange. Provides
additional radial strength to prevent gasket
blow-out and acts as a compression stop.
Type RF-IRSpiral wound gasket for male/female flanges
consisting of a wound component fitted with an
inner ring to bring the gasket flush with the pipe
bore to prevent inward buckling.
Type SG-IRIdentical to Novus SG but also fitted with an inner
ring to prevent inward buckling at the windings.
Type HX-RThis type of gasket consists of a wound compo-
nent fitted with a narrow wound centering ring.
Centering windings ensure correct centering in
flush flanges (e.g. in heat exchangers).
Type RF1The gasket consists of a sealing filler and V-shaped
metal strip wound in combination. This profile is
usually applied to tongue/groove flanges.
Type SG-RTJA standard spiral wound gasket (SG Type) with
dimensions tailored to Ring Joints (RTJ) flanges.
Type HX-RIRThis gasket is identical to HX-R but also fitted with
an inner ring, rendering this gasket type suitable
for mounting in male and female flanges.
Standard Gasket Profiles
Novus produces the following typesof spiral wound gaskets.
7 8
Spiral Wound Gaskets
Profile with a GT - Zone
In the event of a graphite filled spiral wound
gasket possibly causing an undesirable reaction
between the graphite and the medium to be
sealed, or of possible medium contamination,
the problem can be solved by using a spiral
wound gasket with a GT - Zone.
The spiral wound element of a Novus GT - Zone
gasket consists of outer windings of Hi-Temp
ceramic material with a central winding zone
made of graphite or PTFE (depending on the
operating conditions) to improve gas tightness.
This results in a spiral wound gasket with the fol-
lowing properties:
Can be used at higher temperatures.
Has excellent sealing properties.
Combined with the other advantages of a spiral
wound gasket, the spiral wound with a GT - Zone
may be used in a wide range of operating condi-
tions and applications.
Special Profiles Special Shapes
Spiral wound gaskets can be produced in a wide
variety of shapes, such as oval and pear - shape,
with pass - partition bars and many other types.
Generally, the pass - partition bars on spiral
wound gaskets are manufactured as metal -
jacketed bars.
A variety of alternatives are available.
Type MH
This spiral wound gasket is identical to the RF1
profile but oval shaped to fit manholes.
Type TC/HH
This type of gasket is for hand holes and special
flange assemblies (tube cap and hand hole
covers). They are available in e.g. square, rectan-
gular, oval, diamond and pear shapes.
A drawing specifying the correct dimensions are
required to manufacture special shapes.
Type WL
This gasket is identical to RF1 but fitted with
an outer winding. Centering is achieved by
positioning the winding over two bolts opposite
each other.
Type HE
Fitted with pass partition bars for use on heat
exchangers and vessels, this gasket type is other-
wise identical to the RF1 profile. Metal - jacketed
bars have a thinner design than that of spiral
wound gasket material.
The bars are fixed through welding
Type HE-SG
Fitted with an outer centering ring, the HE-SG is
otherwise identical to the HE profile.
Type HE/SG-IR
Fitted with an outer centering ring and an inner
ring, the HE/SG-IR is otherwise identical to the
HE profile.
Material Selection
The material selected for the inner ring and
winding metal is usually the same as the
flange metal. This prevents corrosion and
differential expansion problems. The outer
centering ring is generally manufactured from
carbon steel with an anti- corrosion treat-
ment. However, the ring may also be
manufactured in the same metal as the flange
to prevent corrosion problems.
The table below lists the application limits and
specifications of alloys used in the manufac-
ture of spiral wound gaskets.
Benefits of the Centering Ring
The spiral wound gasket outer centering ring
provides the following benefits:
Optimum location between the bolts.
Protection of the spiral wound element.
Additional security against gasket
blow-out.
Acts as compression limiter preventing
overloading and over compression of the
spiral wound element.
Prevents radial-flow of soft fillers, such as
PTFE.
For these reasons it is preferable to use spiral
wound gasket with outer centering rings.
The outer ring is marked with nominal size,
pressure class, standard and materials.
Benefits of the Inner Ring
The spiral gasket inner ring provides the fol-
lowing benefits:
Prevents radial-flow of soft fillers, such
as PTFE + Graphite.
Reduces turbulence-minimising flow
resistance.
Acts as a heat shield when the spiral
wound gasket is subjected to high
temperatures.
Inner and outer rings are particularly recom-
mended for use on spiral wound gaskets
exceeding class 600lbs, but specifically recom-
mended for high temperatures and pressures
to optimise the operational reliability of the
spiral wound sealing element. Inner rings are
mandatory for PTFE filled spirals.
Spiral Wound Gaskets
109
Material(Trade Name)
Low Carbon Steel
Stainless Steel 304
Stainless Steel 304 L
Stainless Steel 309
Stainless Steel 316
Stainless Steel 316 L(1)
Stainless Steel 316 Ti
Stainless Steel 321
Stainless Steel 347
Stainless Steel 410
254SMO
Duplex
Super Duplex
Aluminium
Nickel 200
Monel 400
Inconel 600
Inconel 625
Incoloy 800
Incoloy 825
Hastelloy B2
Hastelloy C276
Titanium
R St 3.72
X5 Cr Ni 18
X2 Cr Ni 18 9
X15 Cr Ni Si 20 12
X5 Cr Ni Mo 18 10
X2 Cr Ni Mo 18 10
X10 Cr Ni Mo Ti 18 10
X10 Cr Ni Ti 18 9
X10 Cr Ni Nb 18 9
X6 Cr 13
X1CrNiMoCuN20187
X2 Cr Ni Mo N 22 5 3
X2 Cr Ni Mo N 25 6 3
A1 99 5
Ni 99 2
Ni Cu 30 Fe
Ni Cr 15 Fe
Ni Cr 22 Mo 9 Mb
X10 Ni Cr A1 Ti 3220
Ni Cr 21 Mo
Ni Mo 28
Ni Mo 16 Cr 15 W
Ti 99 8
-
1.4301
1.4306
1.4828
1.4401
1.4404
1.4571
1.4541
1.4550
1.4000
1.4547
1.4462
1.4410
3.0255
2.4066
2.4360
2.4816
2.4856
1.4876
2.4858
2.4617
2.4819
3.7025
-
304
304L
309
316316L
316Ti
321
347
410
S31254
S31803/32205
S32750
A91050
N02200
N04400
N06600
NO6625
N08800
N08825
N10665
N10276
R50400
-
304S15/16/13
304S11
309S24
316S16
316S11/13
320S31
321S12/49/87
347S31
410S21
-
318S13
-
1B
3072-76 NA11
3072-76 NA13
3072-76 NA14
3072-76 NA21
3072-76 NA15
3072-76 NA16
-
-
TA2
DINSpecification
DINMaterial No.
AISAASTMUNS
B.S.
- 40
-250
-250
-100
-100
-100
-100
-250
-250
-20
-100
-40
-40
-250
-250
-125
-100
-50
-100
-100
-200
-200
-250
500
550
550
1000
550
550
550
550
500
850
500
300
300
300
600
600
950
450
850
450
450
450
350
7.85
7.90
7.90
7.90
7.90
7.90
7.80
7.90
7.90
7.80
8.00
7.80
7.80
2.71
8.90
8.80
8.40
8.44
8.00
8.14
9.20
8.90
4.50
Temperature(OC)
Minimum Maximum
Density(gr/cm2)
Standard Material for Spiral Wound Windings
Identification
S
S304
S304L
S309
S316
S316L
S316TI
S321
S347
S410
6Mo
2205
2507
AL 1050
Ni200
400
600
625
800
825
B2
C276
Ti2
Outer Winding
Spiral Gasket
Bolt Position
Guide Rings and Material Selection
Spiral Wound Gaskets
The Novus WRI-LP Gasket
Flange corrosion due to the aggressiveness of
Hydrofluoric Acid has been prevalent in chem-
ical units for many years causing expensive
maintenance, repair and replacement costs.
Scheduled maintenance includes cutting and
replacing small diameter flanges that are cor-
roded. Larger flanges are welded and re-faced
when corrosion is too extreme. It is not
uncommon to cut off or re-machine in excess
of 25% of the flanges on site.
The Traditional Solution
Spiral wound gaskets that are typically speci-
fied for this service are manufactured using
monel winding metal and flexible graphite
filler material, carbon steel outer ring and a
filled PTFE inner ring or monel inner ring. The
unsupported ring of filled PTFE contributes
little to seal tightness and can be distorted
during installation. The lack of tightness will
not prevent the flange corrosion that occurs
on the inside diameter of the joint.
Monel inner rings can increase the flange
corrosion by causing a crevice between flange
and inner ring.
The WRI-LP design utilises a unique camprofile
style machined inner ring that is encapsulated
by a layer of PTFE. This PTFE coating is very
durable and chemically resistant. Flexible
graphite or PTFE can be utilised as covering
layers for the machined serrations. The cam-
profile style inner ring is designed to match
the ID of the pipe bore, thus creating an
extremely tight seal that protects the entire
flange surface. This arrangement gives a ‘dual’
seal where the primary seal consists of
the faced camprofile type inner ring, the
secondary seal is created by the graphite
winding element contained within the spiral
wound type gasket.
The life of the flange is extended by the
protection created by the WRI-LP and the
joint maintains fire safety by utilising graphite
covering layers over the inner ring.
In recent years the petroleum refining industry
has placed an increasing emphasis on the safe-
ty of the use of Hydrofluoric Acid in petroleum
refineries. Refineries use the Hydrofluoric acid in
a manufacturing process called ‘alkylation’
which is increasingly important in producing
a high quality gasoline. Hydrofluoric Acid is
hazardous and corrosive and if accidentally
released can form a vapour cloud. In the past
five years, there have been a number of
accidental releases at major petroleum refineries.
Chemical plants utilise HF acid as a process
media and experience similar difficulties.
The Novus Solution
Traditional SolutionThis illustration gives a typical standard spiral
wound arrangement. This profile creates a sig-
nificant void between the inside diameter of the
gasket and the ID of the pipe bore where severe
flange erosion can occur.
Traditional SolutionThis illustration shows a profile using a standard
inner ring constructed of PTFE. There are significant
sizing problems that can occur using this material
and a low level of tightness is achieved once com-
pressed in the flange. Flange erosion can still be an
issue when using this seal arrangement.
The Novus SolutionThis illustration depicts the WRI-LP gasket
design. Under compression, the entire flange
surface is protected and a tight seal is achieved
across the complete raised face of the flange.
CorrosionPromoting Crevice
Standard SpiralSealing Element
CorrosionPromoting Crevice
Inner Ring designed to preventWinding deformationand reduce crevicevolume
Inner Seal can becustomised to thespecific pipe bore
Flexible Graphite or PTFE Facings
PTFE encapsulatedInner Ring
Flexible Graphiteor PTFE filledspiral wound typeelement
Outer Guide Ring
WRI-LP Flange Seal Configurations
Graphite is universally chosen because of its
good chemical resistance, resistance to ageing,
good gas tightness and ability to operate at
high temperatures.
APX2 is an oxidation resistant graphite which
offers the same excellent sealing characteristics
of graphite but can be used at higher service
temperatures.
PTFE is a high quality synthetic material with
the following characteristics: excellent chemical
resistance, resistance to 260OC, resistant to
ageing, excellent gas tightness.
Standard fillersThe table opposite may be used to select the
correct filler. It should be pointed out that
graphite will be the optimum filler in most
cases. Only where graphite could cause media
pollution, or is not chemically resistant, should
the use of another type of filler material be rec-
ommended. In such cases, an alternative solu-
tion might be to select a gasket with a GT-zone.
How to OrderA correct purchase order should contain the
following information.
1. Type of the spiral wound gasket required
2. Standard of the gasket (flange standard)
3. Nominal size and pressure class
4. Material - inner ring
- Metal winding
- Filler
- Outer ring
Example
Novus SG-IR
Dimensions: ASME B16.20
2” 150lbs
SS316
SS316
Graphite
Carbon Steel
Layer Material
Graphite
Graphite APX2
PTFE
Hi-Temp
Hi-Temp + APX2
Temperature(OC)
Min Max
-200 450
-200 500
-200 260
-200 1000
-200 800
MaximumOperatingPressure
(Bar)
400
400
100
5
100
Gas Tightness
Good
Good
Good
Average
Good
Application
Aggressive Media
Aggressive Media
Aggressive Media
Gases
Gases
Spiral Wound Gaskets
11 12
Hi-Temp is MICA based material suitable for
high temperature applications, often used in
combination with graphite (GT-zone).
Non standard materials are available on request.
Filler Material Selection
Properties
Excellent resistance to radical shear
Creates a tight seal at low bolt loads
Can be used when there is insufficient
bolt load to seal spiral wound gaskets
Outstanding resistance to
thermal cycling
Safe to handle and fit
Excellent thermal and chemical stability
Tolerant to flange imperfections
Practical Benefits
No sharp edges for safe handling
Precompressed graphite resistant to
damage and marking during fitting
Excellent rigidity ensures easy posting
between flanges
Does not stick to flanges
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Seating Stress Range
Corrugated gaskets offer reliable sealing
performance when seated within the follow-
ing seating stress ranges
Thickness
Available in 1.5mm, 2mm and 3 mm
Minimum(N/mm2)
20
Optimum(N/mm2)
70
Maximum(N/mm2)
200
Seating Stress (20OC)
Flange Surface FinishThe recommended flange surface finish for
corrugated gaskets with sealing layers is from
3.2 to 6.3um Ra (125-250 RMS), this is also
referred to as a smooth finish.
Sizing Guidelines
DIN Sizes 10, 16, 25, 40 bar.
ANSI Sizes Class 150 and 300lb. Other sizes
available on request. Also available for vessel
and non-standard applications.
Chemical Suitability
PH Range 0-14.
Corrugated Gaskets
Corrugated Gaskets
Novus Corrugated Gaskets comprise of a
corrugated metallic core, normally stainless
steel, with a soft facing layer applied to each
face. The corrugations provide resilience and
reduce the sealing contact surface area of the
gasket while the soft layer ensures outstand-
ing sealing, even at low loads. These gaskets
are particularly suited for heat exchanger
applications as a replacement to metal
jacketed gaskets.
Heat Exchanger Applications
Heat exchanger flanges, owing to the
difference in thickness, of the mating flanges,
heat and expand at different rates.
This differential expansion can cause radial
shearing of the gasket and therefore it is
critical that a gasket is selected which resists
radial shear and maintains a seal even under
thermal cycling conditions.
Corrugated metal gaskets have a proven record
in problematic exchanger applications, offering
low relaxation, high resistance to radial shear
and high levels of tightness. For this reason
these gaskets are replacing many of the
older technologies such as metal jacketed
particularly on heat exchangers.
Layer Material Selection
The following table may be used to determine
the appropriate sealing layer material. Novus
recommend the use of graphite layers for
most applications. Only in cases where
graphite may cause media pollution, or is not
chemically resistant, should an alternative
layer material be chosen.
Layer Material
Graphite
Graphite APX2
PTFE
Hi-Temp + APX2
Temperature(OC)
Min Max
-200 450
-200 500
-200 260
-200 800
MaximumOperatingPressure
(Bar)
150
150
50
100
Gas Tightness
Good
Good
Good
Good
Application
Aggressive Media
Aggressive Media
Aggressive Media
Gases
GraphiteGraphite is a universal, high quality, non
asbestos sealing material featuring - very good
chemical resistance, resistance to high
fluctuating temperatures and pressures, non
ageing properties plus excellent gas tightness.
PTFEPTFE is a high quality synthetic material
featuring - excellent chemical resistance, tem-
perature resistant up to 260OC, good ageing
resistance and excellent gas tightness.
Hi-TempHi-Temp is a mica based material suitable for
high temperature applications, often used in
combination with graphite up to temperatures
of 800OC.
Graphite APX 2Inhibited grade for oxidation resistance. Ideal
for use at temperatures above the limit rec-
ommended for standard graphite grades.
Often used in combination with Novus
Hi-Temp for high temperature applications.
Corrugated Gaskets
1413
Layer Material SelectionHow to OrderA correct purchase order should contain the
following information.
1. Standard of the gasket (flange standard)
2. Nominal size and pressure class
3. Material - core filler
Example
Novus CMG
Dimensions: ASME B16.20
2” 150lbs
SS316 Core
Graphite Coating Layer
Metal Jacketed Gaskets
Metal jacketed gaskets consist of a metal
cover and a ‘soft’ sealing material filler.
The sealing filler provides outstanding
resilience, while the metal jacket guarantees
excellent sealing and protects the filler against
pressure conditions, fluctuating temperatures
and corrosion.
Gasket Profiles
Metal jacketed gaskets can be produced in a
variety of styles. The diagram below shows
the standard range of shapes for vessels and
heat exchangers.
When ordering metal jacketed gaskets with
pass-partition bars, a drawing with the exact
dimensions and positions is required.
Flange Surface Finish
We recommend a maximum flange
surface finish of 1.6um.
Standard Metals
Aluminium
Copper
Stainless Steel
Monel
Nickel
Hastelloy
Soft Iron
Brass
Inconel
Incoloy
Silver
Titanium
Standard Fillers
PTFE
Non-asbestos Millboard
Graphite
Metal Jacketed Gaskets
Jacket material:
Stainless Steel
Aluminium
Copper
Brass
Titanium
Silver
Carbon Steel
Soft Iron
Monel
Inconel
Incoloy
Nickel
Hastelloy
Filler materials:
Non Asbestos Millboard
PTFE
Uniflon
Graphite
S2
S3
S4
S4A
S6
S7
S8
S9
S12
Metal Jacketed Gaskets
15 16
Standard vessel and heat exchanger profilesThe illustrations represent standard Novus spiral wound gasket shapes for vessel and
heat exchanger flanges.
A wide variety of materials are available to
guarantee excellent sealing. The metals listed
on the opposite page are standard, other
metals are available on request.
This type of gasket is being replaced by either
Camprofiles (see page 3-6) or corrugated metal
products (see page 13-14).
Welded Metal Jacketed Gaskets
Welded metal jacketed gaskets are manufac-
tured in a wide range of sizes and styles.
Generally they are used in
Heat Exchangers, Vessels, Pumps, Autoclaves,
Engines, Valves, and Exhaust Systems.
Metal jacketed gaskets require machined
flange faces, high bolt loads and exact flange
alignment to ensure an effective seal. It is for
this reason that Novus recommend the use of
Camprofile or Corrugated Metal Gaskets for
heat exchanger applications.
Profiles
A E I M Q U
B F J N R V
C G K O S W
D H L P T X
How to OrderA correct purchase order should contain the
following information.
1. Type of the Metal Jacketed gasket required
2. Standard of the gasket (flange standard)
3. Nominal size and pressure class
4. Material - Jacket and Filler
Example
Novus Metal Jacketed Type S6
Dimensions: ASME B16.20
2” 150lbs
SS316, Non-asbestos Millboard
Welded bar metal jacketed gaskets offer the
following benefits over one-piece gaskets with
integral bars
Lower price - Typical cost savings 10% to
40% (depending on material).
Quicker delivery - Less time to manufacture.
Technically superior and safer - Extra seal-
ing safeguards give a better gasket.
Longer sealing life - Bars seal independently
of the outer ring.
One-piece Welded
Minimum(N/mm2)
80
Optimum(N/mm2)
110
Maximum(N/mm2)
180
Seating Stress (20OC)
Type S6 Seating Stress
Control of Flanged Joints
17 18
Flange leaks are of major importance to
petrochemical and chemical plants.
It is estimated that around 30% of heat
exchangers will leak in a refinery at some point
often at huge cost to the plant, both in terms of
business loss and also in damage to plant and
environment.
Root cause analysis shows that failures of
flanged joints can be traced to one of the fol-
lowing three factors:
* Design issues, particularly associated with
the loading of the joint or material selection
* The condition of the gasket, bolt or flange
face or piping system
* Improper assembly, including inadequate
loading or installation
Of the three, flange design itself is rarely the
root cause of the problem, and it is rare for fail-
ures to result in a flange redesign. Analysis
shows that most joint failures are associated
with component selection, damaged or defec-
tive components or improper assembly.
Novus Sealing has a world class reputation in
the prevention and elimination of leaking joints
on site. Our reputation is based upon success in
providing innovative and practical solutions to
petrochemical plants throughout the world. On
the following pages you will find details of the
some of the products and services we offer in
the maintenance and care of flanged joints.
For more information please contact our
technical team. Tel +44 (0)1274 878787
Novus Select Software
The suitability of a gasket material in a given
application is dependent on a number of factors
including chemical resistance, temperature and
pressure capability, flange material and flange
configuration and resistance to thermal cycling.
Choosing the right material for the application
can be a difficult and confusing task.
It is equally critical that the prescribed bolt load-
ings are sufficient to seat the gasket under the
service conditions without overloading the gas-
ket, bolting or flange. Consideration must be
given to the minimum and maximum seating
stress of the gasket as well as the relaxation of
the gasket and studs and must allow for any
variation in actual versus specified load through
inaccuracies in bolt loading.
Novus has developed Novus Select, a user-
friendly software program designed to help
with both selection and installation of our prod-
ucts. The program utilises material compatibility
data combined with practical know how to
simplify the selection process, helping you make
an informed choice about which is the correct
gasket for the application.
Training Programme‘Control of Flanged Joints’
The reliability of the flanged joint depends
critically on competent control of the joint
making process. It is common to put
considerable effort into the design process
only for improper assembly to lead to joint
failure. Therefore it is important that joint
making is undertaken by trained and validated
technicians who have an understanding of
the procedure and the underlying principles
and practice.
The Control of Flanged Joints is an industry
recognised training program designed to
ensure that all individuals with responsibilities
in connection with ensuring the safe control
of flange joints are trained and validated as
competent to undertake these responsibilities.
The program, produced in conjunction with a
major global petrochemical company and
leading bolt service company, is based around
a video presentation of best practices and
utilises an intelligent bolting system to explain
and demonstrate these principles.
This unique training method allows key areas
of joint making e.g. the need to use bolt
lubricant, to be clearly understood. Novus Select also calculates the
required bolt stress and torque for a
given application based on the
material limits of both gaskets
and bolts AND the effects of
relaxation and assembly varia-
tion on the gasket stress. Its
user friendly interface simpli-
fies the calculation process
for both standard and non-
standard designs helping to
ensure that the gasket will seal throughout
its service life.
The program can also be modified
by Novus to accommodate plant
specific requirements.
The list of gaskets, bolt grade or lubricant
type can be refined to include only those
which are used on site, making the program
ideal for plant based use.
S E L E C T
Training Programmes can be carried out on-
site or at the Novus Training Centre.
The training covers a broad spectrum of topics
which can be tailored to suit requirements
including:
* Introduction
* Leaks and Emissions
* Flange Design Issues
* Flange Joint Preparation and Assembly
* Systems and Procedures
* Records and Traceability
* Tightening Joints On-Line
* Emission Monitoring
* Control of Fugitive Emissions
In addition to the above program Novus
also offer courses on a range of other topics
associated with flanged joint sealing includ-
ing: gasket manufacture and technology,
software aided selection, installation and
environmental compliance.
Industrial Training Programmes can be tailored to suit different plant requirements
Training on-site
There is also a DVD which accompanies this course.
A DVD presentation explains the principles of best practice.
In order to ensure the optimum service life
of Novus semi-metallic gasket materials it is
not only important to choose the correct
material for the application but to install and
maintain it correctly.
The following guidelines are designed to
assist the end user in the assembly of Novus
gasket materials.
Flange Condition
Remove the old gasket and check that the
flange faces are clean and free from inden-
tations and scoring. Radial (cross face) scor-
ing is a particular concern and can lead to
joint leakage.
For most applications a surface finish of
between 3.2µm to 6.3µm Ra (125 to 250
micro inch) is recommended. For metal jack-
eted gaskets a surface finish of 1.6µm Ra
is recommended. Use a surface finish
comparator e.g. Novus Comparator to check
flange finish.
Check that the flange faces are parallel or
that the pipework is sufficiently flexible to
allow the flanges to be pulled parallel and
concentric without excessive bolt loads.
Gasket
Always use a new gasket
Out of flat or pitted flanges may require
thicker filler or facing materials to accom-
modate the imperfections.
Check that the gasket is in good condition
and that the dimensions are correct for the
class and size of the flanges.
Do not use jointing compounds, grease or
lubricants with Novus semi-metallic gasket
materials. These compounds can affect the
contact friction between the gasket and the
flange and can lead to creep and premature
joint failure.
Bolting
Ensure the bolt and nut threads are clean.
Apply bolt lubrication to the bolt and nut
threads and to the face of the nut to be
tightened. Do not apply grease or bolt lubri-
cant to the joint face. After cleaning and
lubrication it should be possible to run the
nut along the full length of the bolt by hand.
If this is not possible the bolts and nuts
should be refurbished or replaced.
Scrape, wire brush or file as necessary the
back face of each flange where the bolt
heads and nuts are to sit, ensuring that the
surfaces are clean and flat.
If possible use hardened flat washers to
ensure even transfer of the load.
Installation
Ensure that the gasket is installed centrally.
It is recommended that the bolts are tight-
ened using a controlled method such as
torque or tension. If using a torque wrench,
ensure that it is accurately calibrated.
Tighten bolts in a star-like crossing pattern in
the following sequence:
Finger tighten nuts
Tighten to 30% of the final load
Tighten to 60% of the final load
Tighten to full load
Make a final tightening sequence, working
around the flange, tightening each bolt in
turn until the specified torque is achieved.
After Installation
Check that the flange faces are parallel using
a suitable tool e.g. Novus Flange Gap Tool.
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If there is a requirement to fix the gasket to
the flange prior to assembly (e.g. large verti-
cal flanges) then a light dusting of spray
adhesive e.g. 3M 77 spray may be used.
The adhesive should be applied sparingly
and in isolated areas, and must be compati-
ble with the fluid medium.
19 20
Novus Testing Services
In some circumstances, analysis of the
mechanics of a flanged joint by calculation or
finite element modelling is insufficient to
predict performance of in service. In such
cases, it is necessary to use application testing
to replicate the conditions under which the
flanged joint will operate. The data gathered
from such testing can be used to ensure that
the most suitable gasket is being employed
and that it is properly loaded to withstand the
service conditions.
Novus technical facilities allow application
testing under wide range of service condi-
tions. In this capacity, the company has a
world wide reputation for solving even the
most problematic applications including:
High temperature cyclic exchangers
Air compressor flanges
Aerospace engine flanges
High pressure applications
Material compatibility
Testing can be conducted on one of
our test rigs or if required using the
customer’s own equipment.
Our use of Intelligent fasteners allow the load
in each bolt to be accurately applied and more
importantly monitored through the testing
cycle even at elevated temperatures. This
allows service effects such joint relaxation to
be analysed and a solution implemented.
Novus Joint IntegrityDatabase
It is good practice to maintain records of joint
making activity. This means that flanged
joints can be traced back to the technician
who assembled them and that relevant data
on the assembly process can be documented.
HSE guidance note 2/2000 places responsibili-
ties on duty holders in regard to the making of
flanged joints, and in addition to emphasising
the above issues requires that duty holders
maintain adequate records of all joint making
activity. The Novus Exchanger Database is
designed to ensure that the joint making
process is recorded and traceable.
Novus Joint MakingProcedures
Reliable flange joint making requires that all
individuals involved in the process are aware
of their role and implement their duties
correctly. Efficient systems and procedures,
together with careful training and validation
are essential in what can be a hectic mainte-
nance schedule. It has been shown that
organisations that put effort into the
development of joint making systems and
procedures consistently have better results
and have a more highly motivated workforce.
This fact is recognised by the HSE Safety
Notice 2/2000 Bolting of flanged joints for
pressurised systems.
Novus Technical have assisted a number of
plants throughout the world in the produc-
tion of joint making procedures.
The procedures are based on best practice,
combining our expertise in joint making with
practical know how, but are always tailored
to plant requirements.
For more information contact our
Technical Services Team
+44 (0)1274 878787.
Leak Detection and RepairProgrammes
The most effective method of controlling
fugitive emission from process equipment
is through the implementation of a
structured leak detection and repair (LDAR)
program. By identifying the source of the
emission and then taking action to eliminate
or minimise it, major gains can be made
through emission reduction.
In most cases action taken to reduce fugitive
emissions offers excellent financial payback,
enabling the client to sell product that would
otherwise be lost to the environment.
Novus LDAR is the UK’s leading fugitive
emissions control company with a wealth of
experience in the identification and repair
of equipment leaks.
� Cost effective method for major emission
reductions.
� Compliance with environmental legislation.
� Application of Best Available Technology
� Major savings from reduction in product loss.
� Improvements in process efficiency.
� Increased plant safety.
Installation of Novus Semi-Metallic Gaskets
Novus Flange Joint Tool Kit
Poor flange assembly is the most common
cause of gasket leakage and yet experience
shows that good practice is relatively simple to
achieve: Trained technicians working to clear
procedures and with the correct equipment
will result in a properly assembled flange.
Novus flange joint tool kit complements our
Joint Making procedures in assisting techni-
cians in the making of properly assembled and
reliable flanged joints. Each kit contains a
number of effective tools that help to ensure
that the flange has the correct surface finish,
is properly aligned and is assembled correctly.
Novus flange joints kits each contain:
� A flange gap tool
� A Flange Surface Comparator
� A torch for checking flange surface
condition
� A Engineering handbook